Centrifugal pump

ABSTRACT

The invention relates to a centrifugal pump, in particular, a single stage or multi-stage side channel pump in a modular design, wherein the stage or every stage of the pump comprises a preferably divided modular housing with assigned centrifugal impellers, which are designed so as to be self-supporting; and, thus, a pump shaft, which is known in the prior art, is no longer necessary.

The invention relates to a centrifugal pump, in particular, to a single stage or multi-stage side channel pump in a modular design. In this context the stage or every stage of the pump comprises a preferably divided modular housing with an assigned, rotatably mounted centrifugal impeller.

Self-priming centrifugal pumps in the modular design are known from the DE 755 269. The individual modules “2 c” and “d” (FIG. 1) form with the centrifugal impeller “h” a pump stage. At the same time the centrifugal impeller is mounted on a continuous, rotatably mounted pump shaft. Such pumps are manufactured in a variety of models—that is, with different pump stages that vary in number and size. Therefore, a special pump shaft has to be manufactured for each pump model. Relevant for the pump shaft are the shaft diameter, the shaft length and the shaft material.

Since a special pump shaft has to be manufactured for each pump model, the results are, on the one hand, high production costs and, on the other hand, high warehousing costs for the stockpiling of the pump shafts.

The warehousing costs are incurred not only by the manufacturers of the centrifugal pumps, but also by the users of such centrifugal pumps, in particular, if the user uses several different types of pumps and, consequently, has to keep an inventory of the pump shafts for each pump model.

The warehousing costs, incurred by the pump manufacturer, will escalate all the more due to the fact that the manufacturer has to have two different inventories. In particular, one inventory of the raw materials of the shaft and a second inventory of the ready made pump shafts.

In addition, in the case of the centrifugal pumps, known in the prior art, the pump shaft has to be mounted, in addition to the two bearings on the ends of the pump shaft, in each housing module, a feature that necessitates in turn a plethora of bearing points.

The object of the invention is to provide a centrifugal pump, in particular, a side channel pump, with which it is possible to dispense with a continuous pump shaft, which supports the centrifugal impellers, and, in so doing, avoid the drawbacks of the pumps, known in the prior art.

This object is achieved in that each centrifugal impeller exhibits an elongated hub, which is provided on the one side with an inner recess and on the other side with a stub, which can be inserted, so as not to be rotatable, into the inner recess of the following centrifugal impeller.

With this design of the centrifugal impellers these centrifugal impellers are self-supporting to some extent. The staged mounting stays, but an end bearing can be dispensed with, so that the number of bearing points are reduced, as a consequence of which, the total production costs of such centrifugal pumps become significantly more economical.

A self-supporting system for the centrifugal impellers is produced by means of simple plug connections between the individual centrifugal impellers, so that it is possible to dispense with a pump shaft.

One embodiment of the invention is explained in detail below with reference to a drawing.

FIG. 1 is a sectional view of a centrifugal pump.

FIG. 2 is an exploded view showing the plug connection between two impellers.

FIG. 3 is a frontal view in the direction of arrow “A” from FIG. 2.

A centrifugal pump 10 is constructed as a multi-stage side channel pump in the modular design with the modular housings 9 a+9 b and a pump housing 18, which exhibits a suction stage 11 with the suction branch 12 and a discharge stage 13 with a discharge branch 14. Between the two stages 11+12 there are side channel stages 1 a+1 b with the self-supporting centrifugal impellers 2 a+2 b, which exhibit elongated hubs 3 a+3 b, which exhibit on the one side inner recesses 5 a+5 b and on the other side are provided with stubs 4 a+4 b, which can be inserted, so as not to be rotatable, into the inner recess 5 a or 5 b of the following centrifugal impeller 2 a or 2 b. In addition, the centrifugal impellers 2 a+2 b exhibit blades 7 a+7 b as well as the impeller bodies 8 a+8 b. In this design the hubs 3 a+3 b on the side of the inner recesses 5 a+5 b are arranged so as to align with the front faces 6 a+6 b of the centrifugal impellers 2 a+2 b. That is, they do not protrude; and on the other side the stubs 4 a+4 b project beyond the opposite front faces of the centrifugal impellers 2 a+2 b. A drive shaft 15 is mounted rotatably on the other side in a bearing housing 19 with a shaft bearing 16. The drive sided shaft end 20 is free for the connection of a drive motor (not illustrated). The opposite pump-sided shaft end 21 is provided with a stub 4 a, which can be inserted, so as not to be rotatable, into the inner recess 5 a of the first centrifugal impeller 2 a. The stub 4 b of the centrifugal impeller 2 a is inserted into the inner recess 5 b of the second impeller 2 b. In addition, the centrifugal impeller 2 b is provided with a shaft journal 17, which is braced in the pump housing 18.

The essence of the invention lies in the fact that since the centrifugal impellers 2 a+2 b are self-supporting, a pump shaft, which supports the centrifugal impellers 2 a+2 b and which is known in the prior art, can be dispensed with.

LIST OF FEATURES

-   1a+1 b side channel stages -   2 a+2 b centrifugal impellers -   3 a+3 b hubs -   4 a+4 b stubs -   5 a+5 b inner recesses -   6 a+6 b frontal faces -   7 a+7 b blades -   8 a+8 b impeller bodies -   9 a+9 b modular housing -   10 centrifugal pump -   11 suction stage -   12 suction branch -   13 discharge stage -   14 discharge branch -   15 drive shaft -   16 shaft bearing -   17 shaft journal -   18 pump housing -   19 bearing housing -   20 drive sided shaft end -   21 pump sided shaft end -   22 stub of the drive shaft 

1. Centrifugal pump (10), in particular, a single stage or multi-stage side channel pump in a modular design, wherein the stage or every stage of the pump comprises a modular housing (9) with an assigned, rotatably mounted centrifugal impeller (2), characterized in that each centrifugal impeller (2) exhibits an elongated hub (3), which is provided on the one side with an inner recess (5) and on the other side with a stub (4), which can be inserted, so as not to be rotatable, into the inner recess (5) of the following centrifugal impeller (2).
 2. Centrifugal pump, as claimed in claim 1, characterized in that the hub (3) on the side of the inner recess (5) aligns with one of the front faces (6) of the centrifugal impeller (2) and on the other side projects with the stub (4) beyond the opposite front face (6) of the centrifugal impeller (2).
 3. Centrifugal pump, as claimed in claim 1, characterized in that the inner recess (5) and the stub (4) are designed as a non-rotatable plug connection.
 4. Centrifugal pump, as claimed in claim 1, characterized in that the centrifugal impeller (2) is designed with the hub (3) and the stub (4) as one piece.
 5. Centrifugal pump, as claimed in claim 4, characterized in that the centrifugal impeller (2) with the hub (3) and its inner recess (5) as well as with the stub (4) are made of a casting, which no longer has to be machined.
 6. Centrifugal pump, as claimed in claim 5, characterized in that the centrifugal impeller (2) with the hub (3) and the stub (4) are made of a malleable cast iron or a similar material.
 7. Centrifugal pump, as claimed in claim 3, characterized in that the inner recess (5) is configured as an inner polygon; and the stub (4) is configured as an outer polygon that is adapted to the inner polygon.
 8. Centrifugal pump, as claimed in claim 1, characterized in that a drive shaft (15) is mounted rotatably on the one side in a pump housing (18) and on the other side in a bearing housing (19) with a shaft bearing (16), wherein the drive sided shaft end (20) is free for the connection of a drive motor; and the opposite pump-sided shaft end (21) is provided with a stub (4 a), which can be inserted, so as not to be rotatable, into the inner recess (5 a) of the first centrifugal impeller (2 a).
 9. Centrifugal pump, as claimed in claim 1, characterized in that the last centrifugal impeller (2 b), as seen from the drive side, is braced in the pump housing (18) with a shaft journal (17).
 10. Centrifugal pump, as claimed in claim 2, characterized in that the inner recess (5) and the stub (4) are designed as a non-rotatable plug connection.
 11. Centrifugal pump, as claimed in claim 2, characterized in that the centrifugal impeller (2) is designed with the hub (3) and the stub (4) as one piece.
 12. Centrifugal pump, as claimed in claim 3, characterized in that the centrifugal impeller (2) is designed with the hub (3) and the stub (4) as one piece.
 13. Centrifugal pump, as claimed in claim 10, characterized in that the centrifugal impeller (2) is designed with the hub (3) and the stub (4) as one piece.
 14. Centrifugal pump, as claimed in claim 2, characterized in that a drive shaft (15) is mounted rotatably on the one side in a pump housing (18) and on the other side in a bearing housing (19) with a shaft bearing (16), wherein the drive sided shaft end (20) is free for the connection of a drive motor; and the opposite pump-sided shaft end (21) is provided with a stub (4 a), which can be inserted, so as not to be rotatable, into the inner recess (5 a) of the first centrifugal impeller (2 a).
 15. Centrifugal pump, as claimed in claim 3, characterized in that a drive shaft (15) is mounted rotatably on the one side in a pump housing (18) and on the other side in a bearing housing (19) with a shaft bearing (16), wherein the drive sided shaft end (20) is free for the connection of a drive motor; and the opposite pump-sided shaft end (21) is provided with a stub (4 a), which can be inserted, so as not to be rotatable, into the inner recess (5 a) of the first centrifugal impeller (2 a).
 16. Centrifugal pump, as claimed in claim 4, characterized in that a drive shaft (15) is mounted rotatably on the one side in a pump housing (18) and on the other side in a bearing housing (19) with a shaft bearing (16), wherein the drive sided shaft end (20) is free for the connection of a drive motor; and the opposite pump-sided shaft end (21) is provided with a stub (4 a), which can be inserted, so as not to be rotatable, into the inner recess (5 a) of the first centrifugal impeller (2 a).
 17. Centrifugal pump, as claimed in claim 10, characterized in that a drive shaft (15) is mounted rotatably on the one side in a pump housing (18) and on the other side in a bearing housing (19) with a shaft bearing (16), wherein the drive sided shaft end (20) is free for the connection of a drive motor; and the opposite pump-sided shaft end (21) is provided with a stub (4 a), which can be inserted, so as not to be rotatable, into the inner recess (5 a) of the first centrifugal impeller (2 a).
 18. Centrifugal pump, as claimed in claim 11, characterized in that a drive shaft (15) is mounted rotatably on the one side in a pump housing (18) and on the other side in a bearing housing (19) with a shaft bearing (16), wherein the drive sided shaft end (20) is free for the connection of a drive motor; and the opposite pump-sided shaft end (21) is provided with a stub (4 a), which can be inserted, so as not to be rotatable, into the inner recess (5 a) of the first centrifugal impeller (2 a).
 19. Centrifugal pump, as claimed in claim 12, characterized in that a drive shaft (15) is mounted rotatably on the one side in a pump housing (18) and on the other side in a bearing housing (19) with a shaft bearing (16), wherein the drive sided shaft end (20) is free for the connection of a drive motor; and the opposite pump-sided shaft end (21) is provided with a stub (4 a), which can be inserted, so as not to be rotatable, into the inner recess (5 a) of the first centrifugal impeller (2 a).
 20. Centrifugal pump, as claimed in claim 13, characterized in that a drive shaft (15) is mounted rotatably on the one side in a pump housing (18) and on the other side in a bearing housing (19) with a shaft bearing (16), wherein the drive sided shaft end (20) is free for the connection of a drive motor; and the opposite pump-sided shaft end (21) is provided with a stub (4 a), which can be inserted, so as not to be rotatable, into the inner recess (5 a) of the first centrifugal impeller (2 a). 